NHTSA Complaint #11573784 — 2019 SUBARU OUTBACK

My subaru outback has been having an issue with a dead battery, every month for the past 4 months. My dealership has done 2 complete diagnostics, overloading the system, etc. They have come up with nothing on why my battery dies. When I have taken my car in to be checked, it's always with a new battery that is still good. I have had 3 new batteries in the past 4 months, plus multiple charges. Something drains the battery within a month's time. This past visit to the dealership, I have refused to pick up my vehicle because I know it's going to die in a month. I can't live like this, not knowing when it will die. I am most particular about making sure doors and tailgate are completely closed. Is there anything more the dealership should be checking into? Any advice would be appreciated.